A problem that is currently strongly felt is due to the pollution of water and air caused by the presence of organic compounds which may have various origins. For example, some of them, such as trihalomethanes (chloroform, bromoform, dibromochloromethane, dichlorobromomethane), derive from disinfectant treatments consisting of water chlorination, while other compounds, such as carbon tetrachloride, trichloroethane, trichloroethylene and tetrachloroethylene, derive from industrial and domestic emissions of various chlorinated solvents into the environment.
It is known that various devices for detecting organic compounds present in water and gases at very low concentration are currently commercially available and in use.
Some of these devices, although allowing to reach low limits of organic compound detectability, have problems linked to the steps for pre-treatment of the sample, such as extraction, concentration and purification, which considerably increase the analysis times and are costly. Another problem is due to the fact that they do not allow to perform continuous analysis on the samples.
Other devices, instead, such as the one known as MIMS (Membrane Introduction Mass Spectrometry), are constituted by a capillary element which is connected in series to a hollow-fiber polymer membrane inserted in a mass spectrometer.
A problem that is often noted in this kind of device is the fact that the sample, by flowing inside the membrane, causes it to clog and/or break and causes the sample to leak into the mass spectrometer, with very severe consequences for the apparatus.
Another problem that is strongly felt in this type of device is the noise that affects the measurement signal: the measurement signal-to-noise ratio is in fact very small.
The aim of the present invention is to eliminate the drawbacks noted above by providing a device for analyzing organic compounds in which, while using simple instruments, it is possible to achieve high detectability of the organic compounds present in aqueous and gaseous samples, with a more advantageous ratio between the measurement signal and the noise.
Within the scope of this aim, an object of the present invention is to provide a device in which extraction, concentration and introduction of the organic compounds in the mass spectrometer occur in a single stage, thus reducing analysis times.
Another object of the present invention is to provide the capability to perform analyses on aqueous and gaseous samples both in a continuous stream and in discrete samples.
Another object of the present invention is to be able to perform organic compound detectability analyses both in the laboratory and on the spot.
Another object of the present invention is to provide a device which is easy to provide in practice and can be obtained starting from commonly commercially available elements and materials.
This aim, these objects and others which will become better apparent hereinafter are achieved by a device for analyzing organic compounds, particularly in aqueous and gaseous samples, which comprises a duct which is supplied in input by a gas whose pressure can be controlled by means of a regulator connected to a capillary column which is connected in output to a detector for said organic compounds, an adsorbent polymer immersed in a container being interposed between a first portion and a second portion of said capillary column, characterized in that it comprises, between said second portion and a third portion, means for concentrating said organic compounds, said container containing an aqueous or gaseous sample which interacts with said adsorbent polymer adapted to extract said organic compounds conveyed by said gas in passing through said adsorbent polymer toward said concentration means in order to be measured by said detector.